Dashpot



July 10, 1928.

G. C. ST. JOHN DASH POT Filed Dec. 22, 1925 0 m Qm Pu 6 Patented JulyIt), 1928.

Mire s'mrss ret e-sit riser ,FFICE.

DASHPOT.

Application filed December 22, 1926. Serial Ito. 156,436.

The object of my invention is to provide a dashpot in which fluid thatacts as aresistance to the operation of a movable member will not leakaway, whereby the uniformity of operation of the dash-pot will beassured and the required resistance to' the operation of said memberwill be maintained. v

In carrying out my invention I provide a chamber containinga stationaryhead or piston and a hollow movable member having its lower end closed,said head or piston being within said member providing a space for fluidbetween the lower closed end of the member and said head or piston,

whereby when the closed'end of the memper end and open below,

taining a ber operates toward the head or piston the said fluid willresist the movement of said member for steadying the operation of anelement that is connected with said member.

My invention is particularly adapted for use in connection withfluidmeters and I have illustrated my invention with a fluid meter ofthe class set forth and referred to in Letters Patent No. 1,513,016,granted to me October 28, 1924. p

My invention comprises novel details of improvement that will be morefully'hereinafter set forth and then pointed out in the claims.

Reference is to be had to the accompanying drawings forming a parthereof, wherein v Fig. 1- is a vertical section illustrating myimprovement associated with a steam meter of the class referred to, andl i Fig. 2 is a cross section on line 2, 2, in Fig. 1.

Similar numerals of reference indicate corresponding parts in theseveral views.

The numeral 1 indicates a cylinder or shell having a chamber 2 closed atits uphead or piston 3 shown suspended by a rod 4 secured-to the end 2of the cylinder, as by means of a shoulder 1 on the rod bearingagainstthe inner surface of end 2, and a nut on the rod bearing againstthe outer surface of said end. With- 2 is a reciprocative hollow member6, operative in the nature of a p sin the chamber ton closely andslidably fitted within the chamber. The member '6 is shown of cuplikeform, the bore or chamber 6 ofmemher 6 receiving the head or piston 3which tits siidaoly' and said cylinder conbolts 25. snugly against thennerwall of the saidpmember between the ends of its bore. The lower endof member 6 is closed by the head 6 so as to retain fluid, such aswater, in the space 7 between said head 6 and the head or piston 3.Means are provided for charging the space 7 with water or other fluidwhich I have illustrated.

in the form of a longitudinal bore 8 passing through rod 4 extendingwithout the dashpot to be closed by a'plug 9. The outer end of the hereor chamber 6 of member 6 is closed by a cap orcover 10 prov ded with abore 10 slidable along rod 4 as a guide. The member 6 and cover 10 Vmaybe connected together by screw threads.

A chamber 11 is located within inemberLG between the head or piston, andthecover .10.? Bores 10 in cap'10 are adapted to receive a tool forrotating the cap. A passage 12in head or piston 3 provides communicationbetween the chambers 7 and 11. Be-

yond the cap, or cover 10, is a chamber or space 13 in chamber 2 ofcylinder 1 and cap .10 is provided with one or more holes 14 to, providecommunication between chambers 11 and 13. Means are provided forcommunication between chamber 13 at the ut r end of memb 6 and th spacel within chamber 2 atthe opposite end of said member, for which purposeI have shown a longitudinal groove '15 in the outer surface of member 6through which steam may flow from space 1 into, chamber13 "for balancingpressures within the various chambers and spaces. v

The m m er 6 may be c u r reto be controlled 'by said I have.illustrated .-my improved dashepot in connection with a well known typeof steam meter, the memher 6 being shown connected with the valve 16adapted to cooperate with a seat 17 with in a casing 18 having a steaminlet at 19 and a steam outlet at 20. A rod 21 is connected with valve16 and with member 6 for operating said member in accordance withthe-movements of said valve, the member 6 thereby being supported by therod. I

have illustrated the upper portion of rod 21 guided in a bearing-22 in aguide or spider 23 secured upon the valve casing, as by screws 24, theshell or cylinder 1 being shown detachably secured to said casing by Auniversal joint at 26 is shown connecting the member 6 with the, rod 21for ciprocat edby any part whose movement is ease in operation of theparts and to permit free sliding of member 6 within chamher 2. In theform of steam meter illustrated the casing 18 isshown provided with ahollow projection 27, in which a lever 28 is pivoted at 29, the oppositeend of the lever being operatively connected with the rod 21 by means ofthe pin 30 on the lever operative in a groove 31 of the rod in a wellknown way. A recording or integrating machine A, shown supported uponprojection 27, may have a stylus or other indicating ele- I ment adaptedto be operated by shaft 29 in any well known manner customary in fluidmeters. The lever 28 and recording or integrating machine A formno partof my present invention but are similar to'the corresponding partsreferred to in my aforesaid Letters Patent.

The dash-pot is shownlocatcd above the metering valve- 16 and above thesteam chamber 18 of casing 18, from which cham ber steam may flow intospace l and through groove 15 into space 1.3, and may pass through hole1 1 into the chamber 11, for balancing the pressure on the parts. Thespace 7between head or piston 3,and

the end 6 of member 6will be charged with water when the dash-pot isused with a V steam meter, said'head and end being normally spaced asuitable distance apart when valve 16 is upon its seat 17. WVhen thesteam entering casing 18 raises the valve 16 from its seat the rod 21and the member 6 will be raised correspondingly and the water withinspace 7 will be forced against the head or piston 3 by the end 6 of saidmember and thereby will resist the risin of member 6, any excess waterflowing rom chamber 7 through bore 12 into'chamber 11.

The resistance of the water tothe movement of member 6 with the valvewill have the eflect of steadying the operation of the valve due to thesteam passing from inlet 19 to outlet 20 of the casing. Upon descent ofmember 6 with valve 16 the water in space 7 will descend with saidmember and water which may have been forced into the space 11 throughhere 12 will flow back into space 7 to maintain said space fully chargedwith water. In other words, whatever position the member 6 may be inrespectingthe head or piston 3 the space 7 t-herebetween will remaincharged with water for resisting the outward movement of member 6 mallpositions of the latter, and since no water can leak from member 6 thesame Wlll always remain charged. My improvement 'eliminates the dangerof not having water to resist the outward movement of member 6 in anyposition of valve 16 or any other part that may be connected with saidmember for its control. In case steam condenses in the space 13 thewater of condensation may flow back into the casing through groove 15,and

" position.

to admit fluid within the cylinder steam that condenses in space 11 willassure a supply of water being maintained in space The space 11 issufliciently large to contain all the water or other fluid from space '7when member 6 is raised to its maximum In case there should be excesswater or other fluid in space 11 it will be forced therefrom through thebore linto space 13 to flow away through groove 15.

Dash-pots having springs or air resistance against .the operation ofthe'irpistons are known. In such forms of dash-pots theinc'reasedtension oi the springs and the I compression of the air createvariable or increased resistance against the strokes of the piston,continuing when the pistons are at rest, so that the operation of a part'to be controlled is more or less variable. With my improvement theresistance of theffl uid in space 7 'to' the movement of member 6 isconstant so that at all pressures of the valve 16 orthe operating partconnected with member 6 will be the same in all positions of said memberby reason offthe constant supply of fluid in space 7, so that unduefluctuations of valve 16 or the moving part corresponding thereto willbe prevented invarious positions thereof. V w p p v In case my improveddash-pot is used for other purposes than with steam meters 95 water, oilor other suitable fluid maybe used in the space 7 of member 6.

Having now described my invention what I claim is:-'-

1. A dash-pot comprising a cylinder, '2.- hollow member therein havingaclosedlower end to contain fluid, aheadwithin said member normallylocated between the ends of its bore providing spaces withinv the memberon opposite sides of said head, one of said spaces being adapted tocontain fluid between the closed lower end ofsaid memher and said head,meaus providing communication between said spaces for the'flow of saidfluid between said spaces and means llu on'opposite sides of the member.2. A dash-pot comprising a cylinder, a hollow member reciprocativetherein, a head carried by the cylinder and located within the bore ofsaid member, said member having a closed lower end normally spacedit'rom said head providing'aspace therebetween to contain fluid on oneside of the head, the member having a space on the opposite side of thehead, means providing communication between said spaces for theflow offluid therebetween, thecylinder having a space between its outer end andsaid member, and means providing communica- 126 inga closed outer end, ahollow member reciprocative within the cylinder and pro iz-se vided witha closed lower end to retain fluid, a head carried by the cylinder andlocated within the bore of said member and normally spaced from oppositeends of the member providing spaces therein on 0 posite sides of saidhead, means provi ing communication between said spaces and means toadmit fluid within the cylinder on opposite sides of the member. I

4:. A dash-pot comprising a cylinder having a closed outer end, a hollowmember reciprocative within the cylinder and provided with a closedlower end to retain fluid, a head within said member, a rod 'carried bythe closed end of the cylinder and supporting said head within saidmember with spaces within the member on opposite sides of the head,means providing communica tion between said spaces for the flow of fluidfrom one space to another and means to admit fluid Within the cylinderon opposite sides of the members.

5. A dash-pot as set forth in claim 4, in which the member has an openend provided with a cap, the cap having a bore slidably receiving saidrod, a space being provided between the closed outer end of the cylinderand the cap, and means providing communication between said space andthe in terior of t-hehollow member.

GAMALIEL 0. ST. JOHN.

